Waterloo is located in Black hawk county Iowa with a geographic area of 61.6 square miles. The total population in Waterloo is 67,671 with 49.6% male and 50.4% female. Children under age 5 represent 7.0% of the population, under age 18 equal 23.3% of the population and over age 65 is 16.1% of the population. The median household income is $46,942, per capita income is $27,704. There are a total of 28,710 housing units with 59.9% owner occupied. Education includes 30.6% of residents that are high school graduates and 23.4% with a bachelor's degree or higher. The average temperature in Waterloo in the summer is 72 degrees, and in the winter 23 degrees.